Be Perfect (Matt 5:38–48)

Matthew 5

Sermon on the Mount, an 1877 painting by Carl Bloch

A Link to Matthew 5 (ESV)

Be Perfect (5:38–48)

As Jesus moves to the fifth of his six antitheses, he begins by quoting a well-known formula:

An eye for an eye and a tooth for a tooth (5:38).

The line comes from the law itself (Exod 21:24; Lev 24:20; Deut 19:21), but it was never intended as a license for the wronged party to exact revenge on his own terms. In its original setting, the lex talionis was a judicial ceiling, not a floor. It bound Israel’s judges to a punishment that fit the crime and no more, which meant it existed to stop the very thing an insulted person’s instincts demand: escalation. Without it, a broken tooth becomes a broken jaw, and a broken jaw becomes a life. Jesus does not overturn this law so much as remove it from a context where it could be abused.

But I say to you, do not resist the one who is evil. But if anyone slaps you on the right cheek, turn to him the other also (5:39).

A slap to the right cheek is usually presumed to be a backhanded blow, which is usually intended more as an insult to a person’s standing rather than an attempt at injury. The instructions that follow (handing over a cloak along with a shirt already surrendered in a lawsuit, walking a second mile for a soldier who has legally commandeered the first, and giving to the one who asks) all describe the same posture: absorbing loss rather than settling the account.

The sixth antithesis extends this further. “Love your neighbor and hate your enemy” (5:43) does not come from the Mosaic Law. No text demands hatred of an enemy by the people of God. It was an inference some drew by narrowing “neighbor” in Lev 19:18 to the point of excluding anyone outside the covenant community. Jesus removes the boundary rather than adjusting it.

But I say to you, love your enemies and pray for those who persecute you, so that you may be sons of your Father who is in heaven. For he makes his sun rise on the evil and on the good, and sends rain on the just and on the unjust (5:44–45).

The sun and the rain do not check a person’s record before falling on his field. God’s generosity in creation makes no such distinction, and Jesus grounds the command to love an enemy in that same indiscriminate pattern.

That indiscriminate love is what stands behind the conclusion.

You therefore must be perfect, as your heavenly Father is perfect (5:48).

The Greek τέλειος (teleios) echoes the LXX of Deuteronomy 18:13, τέλειος ἔσῃ ἐναντίον κυρίου τοῦ θεοῦ σου, which renders the Hebrew tamim, a word for wholeness or undivided loyalty rather than flawless performance. What Jesus asks for is not moral perfection measured against a scorecard but a love that has stopped sorting people into categories like ‘deserving’ and ‘undeserving’ before it acts.

We keep that scorecard more often than we admit. We reserve warmth for those who have been warm to us first and call it prudence. We extend patience only as far as someone’s conduct has earned it and call it discernment. Jesus is describing something less tidy than our usual modus operandi. He calls for a love that runs ahead of what the other person has done to merit it because that is exactly the love the Father has shown us.

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The Beatitudes (5:1–12)

Jesus opens the Sermon on the Mount with a list that defines those who are “blessed,” and every entry runs against the grain of what any reasonable person would call a blessed life. The poor in spirit. Those who mourn. The meek. Those who hunger and thirst for righteousness. The persecuted. In any human culture, across any century, these are not the categories that define flourishing.

The world has its own definition of blessed, and it tends to cluster around prosperity, power, privilege, and prestige. Jesus does not qualify or nuance that definition. He inverts it entirely.

The clearest signal of what Jesus is doing comes at the end of the list, where he draws an explicit connection to the prophets:

“Blessed are you when others revile you and persecute you and utter all kinds of evil against you falsely on my account. Rejoice and be glad, for your reward is great in heaven, for so they persecuted the prophets who were before you” (Matt 5:11–12).

The prophets were not, by any ordinary measure, successful men. They were rejected, ignored, imprisoned, and killed. And yet Jesus points to them as the precedent for the blessed life. To be persecuted for his sake is to stand in prophetic succession, which means the shape of the blessed life in God’s economy has always looked different from the shape the world assigns to it.

The structure of the Beatitudes reinforces this. The list is bracketed at both ends by the same declaration: “for theirs is the kingdom of heaven” (Matt 5:3, 10). Every promise in between is future tense — “they shall be comforted” (5:4), “they shall inherit the earth” (5:5), “they shall be satisfied” (5:6), “they shall receive mercy” (5:7), “they shall see God” (5:8), “they shall be called children of God” (5:9) — but their possesion of the kingdom itself is present tense because the kingdom has arrived with Jesus. The future promises are not consolation prizes for a difficult present; they are the certain outcome of a kingdom already inaugurated in the ministry of Christ.

In verse 5, Jesus says:

“Blessed are the meek, for they shall inherit the earth” (Matt 5:5).

That promise is drawn from Psalm 37:11, where the meek inherit the land while the wicked, who appear to prosper, are cut off. The psalm insists that appearances are not the final word. Jesus is making the same insistence, now with the announcement that the kingdom’s arrival has set that reversal in motion.

The Christian life is oriented toward the future, not the present. The Beatitudes are not a description of what makes life go well now. They are Jesus' declaration of who is truly blessed. His definition is diametrically different from the definition of the blessed life that the world offers. With Jesus, the way up is the way down, and the way to glory is always the way of the cross.

Fulfilling the Law and the Prophets (5:13–20)

When we discuss the Sermon on the Mount, there’s significant debate about who this message is meant for. Is Jesus speaking to Israel, talking about himself, or addressing the church? The answer is yes—all three.

The Sermon on the Mount primarily addresses Israel. Jesus is urging Israel to fulfill its purpose—to be salt and light to the world. When Israel fails in this mission, Jesus steps in to fulfill it himself. Likewise, the church, aiming to follow Christ’s example, adopts this same mission.

One of the main themes of the sermon is that Jesus has come to fulfill the Law and the Prophets.

“Do not think that I have come to abolish the Law or the Prophets; I have not come to abolish them but to fulfill them” (Matt 5:17).

Jesus was often accused of breaking the law during his ministry, but this usually meant challenging the Pharisees’ interpretation rather than the Mosaic Law itself. However, if we ask, “What does Jesus mean by ‘fulfill them?’,” we might receive an answer different from what we expect.

Jesus doesn’t mean fulfill in the way we think of prophecy and fulfillment. He’s talking about Israel’s vocation—and his own—to obey or fulfill the law and thus be salt and light in this world. This meaning becomes clearer at the end of the sermon.

“So whatever you wish that others would do to you, do also to them, for this is the Law and the Prophets” (Matt 7:12).

Jesus’s entire moral ethic is summarized in this one verse. At its core, the law wasn’t about individual commands but about this fundamental principle: Do unto others as you would have them do unto you.

This ethic conflicts with our most natural instincts. As finite creatures whose instincts are governed by the lowest parts of our brains, we are naturally wired for self-preservation—to have our own needs and desires fulfilled and to prioritize ourselves. To do unto others as we would have them do unto us means to turn ourselves inside out. It requires honestly and realistically facing our basic needs and desires, and wishing them for others rather than ourselves.

The ethic of Jesus isn’t just counter-cultural. It’s counter-instinctual, which is why he called his disciples to deny themselves, take up their cross, and follow him.

If we could live like this—even in small ways—then we fulfill Israel and Christ’s vocation to be the salt of the earth and the light of the world.

“You are the salt of the earth, but if salt has lost its taste, how shall its saltiness be restored?” (Matt 5:13).

In the ancient world, salt was used for preservation. There’s a recurring theme in the Bible that the righteous serve as a reason for God to hold back judgment on the world. That’s one of the reasons why God chose one family and gave them his law—so there would be a people to be the salt of the earth.

And just as Israel was called to be the salt of the earth, it was also called to be the light of the world. Jesus says that this shining, this radiance by which the world will come to know the true God of Israel, happens when God’s people fulfill the law and the prophets by doing unto others as they would have done unto them.

So ask yourself: Where can you practice this ethic today? Who in your life needs you to give your best for them, just as you would for yourself? That’s what it looks like to be salt and light in this world and to fulfill the Law and the Prophets.